DWC - Barney's Farm - Wedding Cake Photo Feminised - Happy for people to post here

Grow Diary - Already up to day 26 - please see below

Hi all, thanks for viewing my grow diary.
Let me make one thing clear off the bat.
I AM HAPPY FOR PEOPLE TO COMMENT AND ASK QUESTIONS - BUT, please take unneccessary negativity elsewhere (Constructive criticism welcome though)

I had been keeping my journal in private and on another forum that is very quiet, then I remembered about this place and well, here I am.

Couple of things to note:
This is only my second ever grow. My first went ok, but lack of environment control and knowledge ultimately led to bud rot and a poor dry/cure.
This is only my first ever DWC grow and I am learning as I grow.

Here is my setup and plant:
AC Infinity Cloudlab 722 Grow Tent (2' x 2' x 7')
AC Infinity Ionboard S22 115w Full Spectrum LED
AC Infinity Cloudline Pro T4 Inline Fan
AC Infinity Cloudforge T3 Humidifier
AC Infinity Cloudray S6 Oscillating Fan (Gen 2)
AC Infinity Thermoforge T3 Heater
Photone App with paid in-app Full Spectrum LED
Light diffuser for iPhone 14 Pro Max for Photone App accuracy
TDS/EC Pen
Mars-Hydro DWC Bucket system (Couldn't be bothered with DIY to save a few quid)
Advanced Nutrients Sensi Grow A&B
Advanced Nutrients Sensi Bloom A&B
Advanced Nutrients Big Bud
Advanced Nutrients CalMag Xtra
Plant Success Great White
H²O² 3% on hand if required
99.99% IPA for sterilising where required
Wedding Cake Feminised Photoperiod - Barneys Farm Seeds

I am only growing the one plant this time round whilst I get the hang of my setup, get it all dialled in on the app so next time is even smoother.
I may even do 2 autoflowers next run.
But let's walk first before we run ay.

Now as the title shows, I am already on Day 26, so this first piece of the diary is going to be somewhat rushed and very compact, then it will be updated every 24 to 48 hours alongside my others.

Days 1 in the case of this journal, starts when the seed was placed into the net pot and into the tent under light.
I did not count the days from germination.

Germination:

Germination was done by placing a seed in warm 0ppm RO water ina dark cupboard for 12 hours.
The seed then cracked open and was placed between 2 moist paper towels in a chinese takeaway tub (The clear plastic kind) in a dark cupboard for 4 days.
I then took the seedling and removed the shell easily to expose the cotyledons. The taproot was about 50mm long at this point.
I put the seedling into its pre-soaked rockwool cube and into my net pot.

Seedling Day 1 to 5:

I put 1 layer of hydroton, followed by the rockwool cube and then filled up with hydroton to cover the cube and pot holes to stop light leaking into the res.
I didn't use a humidity dome as I wanted to use my AC Infinity Controller 69 to create automated programmes for all stages of the plants life to keep it as hands-off in future as possible.
For the first week I kept the following conditions:
Light at 400mm, setting 1 which gave 100umol
12.5l 0ppm RO water in reservoir
Tent temp was all over the place as at this point my heater hadn't arrived and I hadn't protected my grow tent from wildly fluctuating ambient temps and humidities.
Temp avergae was around 19°C (Too cold I know, but keep reading)
RH average was 75%, but again, big swings due to the above.

The plant was top fed every day with mild nutrient solution at an EC of 0.3 to 0.4, I wasn't too accurate at this stage as my main issue was the stability of the tent.

Here are some images of the seedling from Day 1 to Day 5







Grow Tent Insulation Housing

I went to my local timber merchants and purchased what I needed, already cut to length for time saving. They cut the timber for free anyway so it saves me getting my table saw out etc.
Purchased 50mm PIR from my local builders merchants and some silver insulation board tape.
I already had the pocket hole jig and screws.

I had planned what I needed on paper beforehand.

Here is an AI mockup using ChatGPT just to show you the original idea in my head.
ChatGPT made this after I gave it all my ideas, but still didnt understand what I wanted exactly.



Here are some images of the build progress and finished








Seedling Day 8 to 14 - Dialled In Environment

After building the insulation box the stability of the tent was second to none, I can now keep humidity to within a couple of % and temperature to within 0.5°C easily. Even after opening the tent to carry out any checks and top-ups etc, the environment is back to where it needs to be within approx 2 minutes.
Oh, I also took delivery of my Thermoforge T3 heater on the same day I completed the build.

Tent conditions here were now:
Temp average 23°C
RH average 75%
VPD avergae with leaf offset 0.6kPa
Lighting 150umol

Growth now started to speed up, still the roots hadn't hit the reservoir though so it was still slow, also growth slowed by the previous poor conditions, so a slower first week of veg was to be expected.

Here are some images from day 8 to 14

Day 15 to Day 26

OK, so the roots hit the DWC res at about day 12, then growth improved dramatically.
When the roots hit the res, I mixed up my nutrients which was

Sensi Grow A & B - 12.5ml of each
Plant Success Great White - 1.37g (0.011g per litre)

This gave me an EC of 0.6 using the 500ppm scale on my pen
Room temps were kept at an average of 23°C and a RH average of 73%
But when I say average, it didn't swing much outside of that, temp maybe 22.5°C to 23.5°C and RH 70% to 75%
Res temps were constantly around 20°C
Lighting was increased gradually to where we are now at 400umol at 400mm
A reservoir change was carried out at Day 20

I stopped top feeding at this point too as it was unneccesary

Here are some images from Day 15 to Day 20

Day 15


Day 17

Day 17 Roots


Day 20 PPFD


Day 2- after reservoir change





After Res Change at Day 20

At the reservoir change I upped the nutrients to 2ml per A & B for a total of 25ml in 12.5ml
This took my EC to 1.00
I then added 1.37g of Great White to renew the beneficial bacteria (This doesn't change my EC)

I noticed growth really ramping up now.The first week was in no doubt stalled slightly due to the early environment swings, but as it is a photoperiod I didn't care much as I can just veg for an extra week anyway.

You can see some of the leaves aren't symmetrical and missing fans etc, this is either due to the early stress or a genetic flaw.

At this point we have kept a constant 400umol PPFD, a temp with lights on of around 26°C, lights off around 23°C
Humidity changes to keep around 1.00 VPD so lights on is around 65% and lights off is around 60%

I decided to let the plant get up to node 6 before doing any forms of training.
At Node 6 I decided to top at node 5.
I took a bit to decide between 4 and 5 but ultimately decided on 5 to hopefully reduce stress time because of the early issues already adding a week or so.

Below are some images of the plant before and after topping.
I have headed the images with days to make tracking easy.


Day 21 Plant View


Day 21 Roots


Day 22 Plant


Day 23 Nodes


Day 24 Plant

CalMag Deficiency

You will notice in the post above, the colour change of the plant in the last 2 images.
I was noticing a CalMag deficiency due to the use of RO water.
I added 25ml of CalMag Xtra to the res.
This raised the EC to 1.8 which I know is high for this stage, but as I can control how long it has this for and when to lower, I don't mind.

The plant responded well to the extra CalMag and the EC didn't cause any issues.
The plant changed from a lime green to the correct darker green I was looking for.

Going forward I will add half the above CalMag at each res change and see where that takes me.

Here are some more images of the last few days with headings

Day 24 Plant


Day 24 Roots


Day 25 Before Topping


Day 25 Topped


Day 25 7 hours after topping


Day 25 topped site 7 hours after topping


Day 25 roots




The dark patching on the roots is not rot by the way, it's inert powder from the great white.
I am using 10lpm of air from 2 stones so the water is quite vigorous in movement so the sediment doesn't really have a chance to settle and therefor it gets clumped in the roots.

I may switch to Orca for this reason on my next res change, but it isn't causing any harm so we will see I suppose.

Today is Day 26 but my lights don't come on until 5pm, so I only have a couple of AM photographs.

From here the diary will be a bit better formatted and more detailed as I can now do it daily.
Up to this point like I pointed out in post 1, it is compact and dense to get you up to speed, so apologies if any important info is missing, but feel free to ask if you have any questions or observations.

Here are some images of the plant, top site and roots from this morning.

Day 26 AM Roots


Day 26 AM Plant


Day 26 AM Topped Node

Day 26 - Update

Environment

1. Lighting raised to maintain 400umol
2. Temperature keeping at approx 26°C
3. Humidity keeping at around 64.4%
4. VPD keeping at around 1.00kPa
5. Lighting schedule 18/6

DWC Reservoir

1. Water temp 21.5°C
2. Water level had dropped, topped up with 0ppm RO
3. EC dropped from 1.8 to 1.6, so plant is using the CalMag and Nutrients
4. I dont check PH anymore as the Advanced Nutrients PH Perfect makes it possible

Plant Health and notes

1. Plant colouring good
2. Very slight tacoing, but this may be due to the stress induced from topping and the high EC, I will monitor this
3. topping site has healed good, nodes are now starting to grow, expecting a boost of growth in the coming days.

Images below from tonight
In order

Day 26 Full View
Plant close up
Roots
Topping Site
Screenshot of AC Infinity app showing consistency of room

DAY 27 UPDATE

Environment

1. Average temp = 26.5°C
2. Average Humidity = 66.2%
3. Average VPD = 0.98kPa
4. Raised light slightly and increased to setting 6 to achieve 450umol, I will gradullay up this to

Plant

1. Rich green colour
2. No signs of deficiencies appearing or stress
3. Top site healed well and 2 nodes have begun growth
4. No defoliation done yet as I am waiting for the 2 nodes to grow larger
5. Tucked some larger fan leaves back to uncover some lower nodes and the top nodes
6. Roots have grown even further, healthy white growth (camera yellows it slightly due to white balance maybe?)

DWC Reservoir

1. Topped up with 0ppm RO water
2. EC has dropped further to 1.55 which indicates the plant is still drinking water AND feeding nutrients
3. Water temp approx 22°C (will monitor)

Images below in order:

• AC Infinity Tent Screenshot
• Plant Full View as it was on opening tent
• Plant topped node
• Plant after tucking leaves
• Plant roots

Your plant is looking really good. Excellent color, zero sign of nutrient imbalance, temp is a tad low (28-29 would give a higher growth rate), water temp is a bit high (20° is slightly more O2 and less chance for root rot)

Great formatting for the journal, too!

Re "two plants next time" — that's possible in a 2' x 2' but doubtful in soil and painful if you're "doing things right". Hydro allows very fast growth and, when plants grow quickly in veg, they tend to be very large by the end of their lifecycle.

A few things that popped up as I read through your posting.

Photone and 450µmol — Photone may be accurate or it may not be. In my testing, it was reading significantly high and, based on the spectrum of the light you're using, I suspect that your actual PPFD is lower than 450µmol. Per my signature block and my postings here and on other sites, you'll see that I advocate feeding my cannabis plants well. At 26 days, 450µmol is well below the light level at which you will maximize crop yield and crop quality. My belief is that cannabis matures its ability to process light at about week 5 and both autos and photos will thrive at light levels about 50% higher than you're giving your plant. From the perspective of the plant, gradually "inching" PPFD upwards from 450 is well intentioned but isn't needed. Light is how plants make food. If you give them too much light, they'll let you know. At day 26, my plants are at about 750µmol.

Re "EC has dropped further to 1.55 which indicates the plant is still drinking water AND feeding nutrients" - if plants are transpiring, which they should always be, they're taking up nutrients. EC may or may not change as nutrients are taken up. When I started growing I found the "Wonder Chart" for DWC and I thought it was a godsend. Until it failed me completely and when I started reading up on how nutrients work in hydroponics.

In the sentence before the "EC dropped further…" you said that you added RO. Adding RO will dilute the solution and that will lead to a drop in EC. On the other hand, when a nutrient solution is fresh, the N, P, K, and Mg (it's either Mg or Mn) will be removed from the solution very quickly (in a matter of hours in a small res) yet they may have no impact on EC. OTOH, calcium is taken up relatively slowly and it has a much larger impact on EC. EC is useful to ensure that your nutrient solution is mixed correctly. After that, it's only a very loose indicator about what's happening in a res and, in a small res like you have, I wouldn't put much stock in it at all.

You're doing "RO add backs" - I've used that approach as well as adding back with full strength nutrients. Both have worked well for me. Why did you decide on that approach? I've attached two papers on res management that you might find useful. The Bugbee paper touches on the how the different uptake rate of nutrient chemicals impact EC. That's also a topic a scienceinhydroponics.com.

Re. topping—I've always topped and LST'd my plants but it was only last week that I found research that discusses the impact on yield. Turns out there is a demonstrable positive impact. I did it because it allows me to get a flat canopy but there's more to it than that. Let me know if you're interested in that and I'll upload the PDF's.

Where to top? I top above the fourth node and I learned the hard way to top about 1"/2cm above the node. You've topped a little low and, as happened to me (more than once!), you might find that the stem splits at that juncture. It looks pretty bad but the wound is healed so I suspect it just looks bad.

Root color - if they're tan, dark tan, or brown and have an odor that's root rot. In the photos, the color saturation decreases toward the end of the roots which indicates to me that it's just stain from the nutrients.

Re light levels — I'm a big believer in "the research". When I started growing in 2021, I followed what I've come to call the "legacy light levels" but, when I did any reading up on cannabis lighting, the research was at odds with the conventional wisdom of "300, 300-600, and 600+" By my third grow, I had changed my approach completely and I've never looked back. Since that time, 2022, research has flooded into the public re. lighting and it's clear that cannabis thrives at high light levels. I've grown at 1kµmol for years and yield and quality has been excellent. In short, there's nothing to support idea that legacy light levels will maximize yield or quality—it's simply inertia. (As for the chart at growlightmeter.com, that's just…silly.)

Below are the daily light values from my most recent grow. I can't say without reservation that they're appropriate for your grow but, based on what I'm seeing, your conditions are very similar to the conditions in which I grow my plants so, overall, while your grow many not support these light levels, it's also arguable that it will.

One difference is that my temps were at 30° and the higher temperature may allow the plant to photosynthesize faster. Second, my plants have been Gelato, once, and multiple grows with Gorilla Glue genetics. Those cultivars may support higher light levels than Wedding Cake. Genetics is a key issue.

My thoughts - we know that cannabis will grow, in ambient CO2, at PPFD's between ~60 and "800-1000µmol" and a grow at 450, gradually rising to 600+ will yield a healthy crop. We know that cannabis will thrive at 1000µmol, as long as light is the limiting factor, and at that light leave will be 15 - 20% larger a crop grown at 800µmol.

Light levels from most recent grow


Family portrait of most recent grow.

Day 22


Day 26


Day 89 (Donna on the left, Erica on the right)


Yield was less than expected because I broke off two of Donna's branches over the course of the grow.


Your plant looks great and you're approaching "the problem" systematically and I think you're going to have a great crop. Keep up the good work!

Thanks to Delps8
Also a day 28 to 31 update

Thank you for such a thought out response.
I will try and address all you have said below

I can raise the temp in the tent without issue using my thermoforge heater.
Ill give it a shot, but I read the ideal temp was between 21 and 29 so I went with 25°C to 26°C

I did wonder if the plant can handle more light and I have seen other growers give much more than I am.
I have just increased the light to 650umol so I will let you know how they take it in around 24 hours or so.

So are you saying I should be topping up with full strength nutrients?
I was just under the impression if the plants are looking healthy and EC is dropping, then I am good as long as it doesn't drop too low or show deficiencies
Here was my plan.
Add nutrients and check EC, add CalMag and check EC
Each day top up with 0ppm RO and check EC

Root colour = The roots are healthy, the brown stuff is the inert powder from the Great White and slight staining as the Sensi Grow Part A is a very deep red, picture beetroot juice.
The roots have no slime, smell or funkiness to them.
There is also no film or slime in the reservoir.

Tonight I noticed some slight lime greenness to the newer growth so I added anoth 0.5ml of CalMag per litre, then I added extra base nutrients to bring the EC back up to 1.8

Here are some images over the previous few days labelled.

Day 28, full plant


Day 28 Roots


Day 30 Topped Node Heal


Day 30 Roots


Day 31 Roots


Day 31 LST

Plants are looking good and the LST is going to help with canopy management. After an LST session, they look kinda beat up—I refer to it as "looking like a wet dog".

Roots look a lot bigger, a good sign.

There's a bit of "nute burn" in one leaf. Nutrient water?

When cannabis goes through a growth spurt, you may see tip burn due to, trying to think how it was explained, the increased transpiration results in Ca being "stranded" in the leaf tips. You can either drop EC a bit, lower PPFD a bit (to slow down growth), or do nothing since it's usually temporary. I go with the latter and haven't had any significant issues.

Vapor88 said:

Thanks to Delps8
Also a day 28 to 31 update

Thank you for such a thought out response.

Click to expand...

You're welcome.

Vapor88 said:

I will try and address all you have said below

I can raise the temp in the tent without issue using my thermoforge heater.
Ill give it a shot, but I read the ideal temp was between 21 and 29 so I went with 25°C to 26°C

Click to expand...

26° is on the cool side. If you can do 28 during lights on, you'll get slightly higher photosynthesis. The key metric is the leaf temperature because that's the actual environment where photosynthesis and other processes are taking place.

During a "conversation" with chatGPT is had a "blinding flash of the obvious" that, perhaps, one reason why I've been able to run high light and high temps is because I tend to have a significant leaf temperature offset in my grows. For my most recent grow, it was -6°F so, when my ambient temp was, say, 83°, the leaf temperature was only 77°.

It seems that most growers have a -2°F offset. If that's the case for you, you could bump your ambient to 28 and still we well away from causing sort of heat stress to your plants.

A key issue when reading a study, and I do forget this from time to time, is that some research is done using elevated CO2 levels and some isn't. If the 29°C number is in an enhanced CO2 environment, that's going to be a few degrees higher than it would be in ambient CO2.

Vapor88 said:

I did wonder if the plant can handle more light and I have seen other growers give much more than I am.
I have just increased the light to 650umol so I will let you know how they take it in around 24 hours or so.

Click to expand...

That shouldn't be a problem. You appear to have an "optimal" environment so I would expect that your plant would welcome the addition 100µmol per day of "food".

Vapor88 said:

So are you saying I should be topping up with full strength nutrients?

Click to expand...

That's a viable option. I've done full strength add backs (Bugbee prefers this) and I've done RO add backs and swap yo've added back a volume equal to the reservoir or when pH becomes unstable(Cannastats - attached - and Fernandez at scienceinhydroponics.com).

Both approaches have worked well for me but my setup is an outlier because of the large volume (28 gallons for one plant). For all reservoirs, there's no reason to swap a res every 7days other than it's convenient. The cannastats paper touches on the validity of that approach.

Vapor88 said:

I was just under the impression if the plants are looking healthy and EC is dropping, then I am good as long as it doesn't drop too low or show deficiencies
Here was my plan.
Add nutrients and check EC, add CalMag and check EC
Each day top up with 0ppm RO and check EC

Click to expand...

The wonders of "CalMag"…

Cannabis needs about 18 chemicals in fertilizer. Ca and Mg are two of those nutrients and, if a product "CalMag" is called for by the nutrient manufacturer to provide Ca and Mg at the required levels, then it should be mixed with the other ferts. When growers have nutrient imbalances, they often reach for "the CalMag" even though there's a very good chance that adding Ca and Mg will only make things worse.

Nutrient deficiencies and toxicities are caused by improper availability and/or improper uptake. If you mix the ferts correctly, availability is not an issue in hydro. The quick check is to measure the EC of your new solution. It should match the EC that's listed on the bottle. If it does, redo the batch. If it matches, it's highly likely that you have the correct formula.

Once the res has been replaced, N, P, K, and Mg (or Mn - I have a mental block on that) are taken up very quickly but those chemicals have very little impact on EC. Every grower checks EC and gets a warm fuzzy when EC has dropped because the plants are "eating". That could be the case or it could be completely wrong. Plants don't "eat". In terms of mass, 90% of nutrients are taken up by water uptake—If your plant is transpiring, it's taking up nutrients. With a small res, per the Bugbee paper, the N, P, K, and Mx will be taken up in a matter of hours but EC will change very little so the grower has no idea what's going on. It's only when the other chemicals are taken up that EC starts to change because the chemicals that are taken up more slowly are the ones that have a greater impact on EC.

There's no problem with checking EC, I have an EC and pH monitor, but it's only a rough guide as to what's happening in the res because it's a fallacy to think that "plants aren't feeding" if EC doesn't change. That's simply wrong.

The Cannastats paper is a quick read, the Bugbee paper has more info in it and it's informational rather than providing guidance on res management. Bugbee advises topping off with nutrients in a YouTube "short" video that he did. It's one of a series of shorts that he did for Athena. Check that one out, specifically, but almost all of his videos are well worth watching.

When you add RO, EC will drop because you're diluting the concentration of chemicals in the reservoir.

For my most recent grow, I did nutrient add backs and I saw no issues. I've also done RO add backs, as is discussed in the Cannastats paper. I suspect that both methods have worked well due to the fact that I've to a large nutrient volume. It's 28 gallons for 8 square feet of grow space which is slightly above the value that the Cannastats paper recommendes.

Which approach is better in a 5 gallon bucket? I really don't have the knowledge and expertise to argue one way or the other but the proof is in the pudding, so to speak. Your plants look great so keep doing what you're doing. You might want to try something different, perhaps to save on labor, but with just the one plant I would think res maintenance isn't onerous. If you move to a larger tent and add a few more buckets, well that's a different story.

Vapor88 said:

Root colour = The roots are healthy, the brown stuff is the inert powder from the Great White and slight staining as the Sensi Grow Part A is a very deep red, picture beetroot juice.
The roots have no slime, smell or funkiness to them.
There is also no film or slime in the reservoir.

Click to expand...

Excellent. Healthy roots smell light "fresh dirt" and the newest roots (the ones at the bottom) will be a bright, white color.

Vapor88 said:

Tonight I noticed some slight lime greenness to the newer growth so I added anoth 0.5ml of CalMag per litre, then I added extra base nutrients to bring the EC back up to 1.8

Click to expand...

Light green could be not enough N or simply not enough nutrients. If VPD is in range, that will cut down on the chances of having a significant imbalance. Fernandez (scienceinhydroponics.com) says that 50% of nutrient imbalances are when VPD is out of whack.

The website scienceinhydroponics.com has a lot of good info but it can be frustrating to find some of the articles. Below are links to the pages that I've found most interesting: